Merge pull request #7652 from Snuffleupagus/resize-event-handler-prevent-error-before-eventBus-initialized

Prevent errors if the 'resize' event is fired before the `eventBus` has been initialized

web/app.js

@@ -1803,6 +1803,9 @@ function webViewerUpdateViewarea(e) {
 }
 
 window.addEventListener('resize', function webViewerResize(evt) {
+  if (!PDFViewerApplication.eventBus) {
+    return;
+  }
   PDFViewerApplication.eventBus.dispatch('resize');
 });